Incandescent lamp.



FRANZ SKAUPY, OF BERLIN, GERMANY, ASSIGNOJR. TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

INCANDESCENT LAMP.

No Drawing.

To all whom it may concern Be it known that I, FRANZ SKAUPY, a subject of the Emperor of Austria-Hungary, residing at Berlin, Germany, have invented certain new and useful Improvements in Incandescent Lamps, of which the following is a specification.

My invention relates to incandescent lamps and particularly to lamps having me tallic filaments, and its object is to prolong the useful life of suchlamps.

My invention consists in an improvement in the arrangement described in my former application, Serial No. 590,499, filed Nov. 3, 1910. In that application I disclosed means for preventing the blackening of the bulb of a metal filament lamp, such as a tungsten lamp, with a consequent prolongation of-its useful life, which consisted in inserting in the lamp a compound which would slowly break down during the operation of the lamp and give off in very small quantities a halogen gas such as chlorin, which would combine with the metal volatilized from the filament and deposited on the bulb, and thereby produce a deposit much less light obscuring than though the deposit were formed of uncombined metal.

My present invention consists in providing another arrangement for slowly giving off the desired gas. All of the halogens will serve the purposes of my invention but I prefer to use chlorin. Instead of using a compound of the chlorin or other gas, I provide a porous substance, such as a body of amorphous carbon, which contains the gas Which is to be given off. This arrangement has the advantage as compared with that of my former application that the rate at which the gas is given off can be more exactly fixed, and the atmosphere more exactly maintained at the pressure of a firstclass vacuum, or about 1/1000 of a millimeter of mercury, or less. This rate has an important effect on the degree of prolongation of the lamp life. Furthermore, certain of the chemical compounds which are adapted to give up the desired halogen gas, as de scribed in my former application, give up, in addition, matter which is not easily volatilized, and which under some circumstances forms deposits which although they are light in color yet injure the appearance of the lamp. 'All such deposits are avoided by my present invention. I may use any porous Specification of Letters Patent.

Application filed March 9, 1912.

Patented Nov. 106, 1015.

Serial No. 682,810.

body which is unaltered in structure or properties during the life of the lamp by,

suitable in its various forms, such as wood charcoal, animal charcoal, sugar carbon, and lamp black. The amount of gas to be given off in a unit of time may be varied within certain limits by varying the porosity and the amount of the carbon introduced. The carbon may in the-first place be completely saturated with the halogen or equivalent gas, and then, while the lamp is on the pump and suitably heated, a portion of the gas may be drawn off and the lamp then sealed. In this way a suitable reservoir of halogen may be provided, which contains no other volatile substance, so that no light obscuring deposits prejudicial to the long life and appearance of the lamp can be made during the life of the lamp. Furthermore,

if amorphous carbon is heated in a stream of chlorin, for example, in order to prepare it for the intended purpose, it retains absorptive power for other gases, and thus may, while giving up halogen, at the same time absorb to a certain extent, harmful gases which may be given ofi by different parts of the lamp in operation. Thus it is possible, in lamps in which, as described in my former application, metallic compounds of halogen are used, to employ carbon saturated with a halogen for the purpose of taking up objectionable decomposition products of the compound without preventing the generation of halogen.

The porous substance employed in my present invention may be secured within the lamp in any suitable manner.

What I claim as new and desire to secure by Letters Patent of the United States, is-

in, and a body of amorphous carbon within said envelop containing a halogen vaporizable in small quantities during the operation of the lamp.

3. An incandescent lamp comprising a sealed and evacuated envelop, a metallic filament therein, and a porous substance in said envelop unaltered during the operation of the lamp and containing a halogen, the metal volatilized from the filament being capable ofcombining with the halogen to form translucent deposits on the bulb, said halogen being vaporized during operation of the lamp to maintain in said envelop an atmosphere of said halogen at the pressure of a first-class vacuum.

4. An incandescent lamp comprising a sealed and evacuated envelop, a tungsten filament therein, and a porous body in said envelop unaltered during operation of the lamp and impregnated with a halogen vaporizable during the operation of the lamp to maintain in said envelop a halogen atmosphere at the pressure of a first-class 5. In an incandescent lamp, a sealed and in, and a body of amorphous carbon within said envelop containing volatile matter continuously vaporizable in small quantities during the operation of the lamp and forming compounds with the metal volatilized from the filament.

6. An incandescent lamp comprising a sealed and evacuated envelop, a tungsten filament therein, and a mass of amorphous carbon impregnated with chlorin and mounted in said envelop in position to maintain during the operation of the lamp an atmosphere of chlorin in said envelop at the pressure of a first-class vacuum. 7. In an incandescent lamp, a sealed envelop, a tungsten filament therein, a carbon body within said envelop containing a halogen, forming tungsten compounds with vaporized tungsten under operating conditions in the lamp.

In witness whereof, I have hereunto set my hand this 21st day of February, 1912.

FRANZ SKAUPY.

Witnesses HENRY HASPER, WOLDEMAR HAUPT. 

